1. Technical Field
The present disclosure relates to cooling fans typically used in electronic devices, and more particularly to a rotor of a cooling fan.
2. Description of Related Art
Cooling fans are widely used in electronic devices for dissipating heat from heat generating components. A cooling fan often includes a stator, and a rotor rotatably connected with the stator. The cooling fan generates airflow to the heat generating components when the rotor rotates. However, because the rotor is typically formed by injection molding, the weight distribution of the rotor is rarely uniform. Accordingly, the rotor is unbalanced during rotation, which results in noise during operation of the cooling fan.
To solve this problem, in manufacturing of a cooling fan, the weight balance of the rotor can be calibrated. This is done by disposing equilibrium clay on the rotor. Typically, the equilibrium clay is filled onto an inner surface of a hub of the rotor by a tool. However, a magnet included in the hub is liable to be scratched by the tool, and the clay can adhere to the magnet. Both these difficulties can adversely affect the performance of the rotor. In addition, it is inconvenient to fill the equilibrium clay into the inner surface of the hub, and thus the manufacturing of the rotor is time-consuming.
What is needed, therefore, is an improved rotor and cooling fan which can overcome the limitations described.